Combined sealing plug and tubing hanger



April 15, 1958 A. F. RHODES 2,830,666

COMBINED SEALING PLUG AND TUBING HANGER Filed July 12, 1956 2 SheetsSheet 1 A ril 15, 1958 A. F. RHODES COMBINED SEALING PLUG AND TUBING HANGER aes TOR.

Filed July 12, 1956 United States COMBINED SEALING PLUG AND TUBING HANGER Allen F. Rhodes, Houston, Tex., assignor to George A. Butler, Houston, Tex.

This invention pertains to a combined sealing plug and tubing hanger for use in well completion apparatus, usually at a joint between vertically adjacent well head elements such as, for example, between the upper end of a tubing head and the lower end of a tubing head adapter which surmounts the tubing head. The device of this invention combines in one piece of equipment a seal between adjacent elements of well completion apparatus, a tubing hanger for supporting the tubing running to the upper of said adjacent elements from the well, and a check valve means for controlling the flow through the tubing.

A principal object of the invention is to provide in a single apparatus means for sealing off across a joint between upper and lower elements of well completion apparatus and means for supporting a tubing in the well.

Another object of the invention is to provide in such apparatus a dependable seal whereby no intermixing will take place at said joint between materials within and without said tubing and above and below said joint of said well completion apparatus.

Another object of the invention is to provide such an apparatus which is compact, has few parts, and is manufactured at low cost.

Another object of the invention is to provide such an apparatus wherein a single unitary body forms all of the functional elements of the apparatus.

A further object of the invention is to provide such apparatus which may be safely and easily installed and which is safe in use.

A still further object of the invention is to provide such an apparatus which will replace a plurality of uncombined devices and which will efilciently perform .the functions of all of the uncombined devices which it replaces.

Briefly described, a preferred embodiment of the invention comprises a plug adapted to be sealed into recesses formed in well completion equipment above and below the plug. Usually the plug will be across a flange connected joint between two elements of well completion equipment, for example, across a flange connected joint between a tubing head and a tubing head adapter above the tubing head. The plug is sealed at its top into a recess in the lower end of the upper element and is sealed at its bottom into a recess in the upper end of the lower element, the seals preferably being effected by a plastic sealant material contained in an annular space between a movable spring-biased barrier and a metal-to-metal seated joint, the sealant material being urged to enter the metal-to-metal joint by the spring and by the equipment pressure. The plug has an axial passage across the joint between the well completion elements, and the lower end of the axial passage is provided with a threaded socket into which a well pipe may be screwed and thereby hung or supported in the well. The plug is adapted to be held down by lockscrews provided in the well completion elements, whereby blowout preventers may be safely removed before completing the assembly of the well completion equipment above the plug. The plug is adapted atet 2,830,666 Patented Apr. 15, 1958 to receive a check valve means within its axial passage for control of the passage of fluids within the well pipe supported by the plug. The plug, depending on the requirements of the well, may be used in the combination capacity described above, or it may be used solely as a joint seal means or solely as a pipe hanger means, and the check valve means within the plug may be included or omitted as desired. Therefore, the invention is very versatile in application and use. In its combination capacity, the apparatus of this invention will replace combinations of two or more separate pieces of equipment heretofore provided for the same purpose.

Additional objects, uses, advantages, and improvements of the invention will appear from the following description of a preferred embodiment thereof, reference being made to the accompanying drawings, of which:

Figure 1 is a vertical section of the preferred embodiment;

Figure 2 is a horizontal section taken at line 22 of Figure 1; and,

Figure 3 is a perspective of the back pressure valve means of the preferred embodiment.

Referring in detail to the drawings, Figures 1 and 2 show the plug body 10 of the combined sealing plug and tubing hanger installed within a joint between an upper member 11 and a lower member 12 of Christmas tree well completion equipment. The member 11, for example, may be a tubing head adapter, and the member 12, for example, may be a tubing head. The invention may equally well be used at other locations in well completion equipment or in other equipment.

The member 11 has lower flange 13 which is bolted to upper flange 14 of member 12 by bolts 15 and nuts 16 in the usual way. The members 11 and 12. have substantially identical downward and upward facing bore recesses 17 and 18, respectively, to receive the body 10.

The plug body M is generally spool-shaped, and has an upper socket portion 19 having threads 20, and therebelow an outwardly formed seat flange 21 having upper conical seat 22 and lower conical seat 23. The upper threads 20 may be used for connecting other equipment above the plug body and may also be used as a connection to the plug body for handling it during installation. At its lower end, body It) has socket portion 24 having threads 25 and seat flange 26 having lower conical seat 27 and upper conical seat 28. Seats 22 and 27 are identically pitched and seats 23 and 28 are identically pitched, the latter having a greater pitch than the former. The body 10 is usually symmetrically formed at its exterior, the seat flanges 21 and 26 being identical and the exteriors of socket portions 19 and 24 being identical.

A small right-angled shoulder 29 is formed above seat flange 21, and an identical shoulder 30 is formed below seat flange 26. The center section 31 of body 10 is cylindrical and it extends between and connects seat flanges 21 and 26. At its interior, body 10 has an axial bore of varying diameter between upper threads 2d and lower threads 25. The upper bore portion 32 is cylindrical and has a larger diameter than other portions of the bore. Below portion 32 is a cylindrical threaded formation 33 slightly smaller in diameter than portion 32. Below threaded formation 33 is a short downwardly converging seat 34, and therebelow a reduced cylindrical bore portion 35 which extends almost to lower threads 25,

being separated therefrom by a slightly further reduced short cylindrical section 36.

The bore recesses 17 and 13 together form a chamber within which body ii) is disposed. A sealing space 37 is provided above recess 17 in member 11 and a similar sealing space 38 is provided below recess 18 in member 12, these spaces being symmetrically disposed about the upper and lower ends, respectively, of body 10. Recesses 3 17 and 18 have conical seat surfaces 39 and 40, respectively at their ends and their diameters are slightly reduced adjacent thereto at 41 and 42 so that a close fit is had around the outer surfaces of seat flanges 21 and 26, as well as at the conical seats 22 and 27, the pitch of seats 22 and 27 being the same as the pitch of seat surfaces 39 and 29. An O-ring packing 43 is disposed in a groove around seat flange 26 to provide temporary sealing means around the lower end of the apparatus during installation. If desired a sealing means may also be provided around seat flange 21 or at either or both of the conical seats to provide temporary seals during installation of the apparatus. The conical seats 23 and 28 at the inner sides of seat flanges 21 and 26 provide means for engaging lockscrews for holding down the equipment during installation. In the preferred embodiment, a plurality of lockscrews 4 are provided in flange 14 to engage seat 23 of seat flange 26, and lockscrews may also be provided in flange 13 to engage seat 2 3 of seat flange 21 if required.

The upper and lower ends of body it are sealed into the respective seal spaces 37 and 38 by plastic sealant means. In seal space 37, a barrier 45 is urged downward toward seats 22 and 39 by a helical spring 46. A plastic sealant injection port 47 provided with an Alernite or other grease fitting 48 is provided to introduce sealant adjacent shoulder 2%, which serves to prevent barrier 45 from covering port 47, an annular space being provided between the shoulder and port through which the sealant flows from port 4 7 to below barrier 45 in seal. space 37. An identical sealing means is provided in seal space 38, being inverted with respect to seal space 37, and comprising barrier 49, spring Sit, sealant port 51, and fitting 52. These seals are disclosed in an application for U. S. patent, Serial No. 401,484 filed December 31, 1953 by Allen F. Rhodes and Robert Eichenberg, and entitled Seal. The seals are effective at very high pressures, the barriers forcing sealant into minute openings between the conical seats to form a very tight seal when a pressure is exerted on a barrier opposite the sealant containing space between the barrier and conical seats.

Referring to Figures 1, 2 and 3, a check valve means, which may be any suitable type known in the art, is disposed in the axial bore of body to check the upward flow through the bore, particularly during installation. The check valve means shown by way of example has an upper portion having an upper threaded socket 60, an upper exterior thread formation 61 which is screwed into threads .33 of the bore, an outer downwardly converging conical seat 62 having therearound a groove 63 in which is disposed O-ring packing 64, and a reduced threaded nipple portion 65, an axial bore 66 extending downwardly from the socket 69. The lower portion of the check valve means comprises a threaded socket r57 adapted for screwing onto nipple 65 of the upper portion, a recess below socket 67 to receive a ring seat 63, a vertically slotted wall section 69 having therearound a plurality of vertical slots 76, and a conical bottom The upper threaded socket til} may provide a connection with other well completion equipment but is primarily provided as a connection for handling the check valve for installation or removal. A ball valve 72 is disposed within the slotted wall section 69, the ball valve 72 being biased upwardly therein against seat 68 by a helical spring 73 which acts in compressive relationship between ball valve and the conical bottom The ring seat 68 is held securely in place between the lower rim of nipple 65 and the bottom of socket 67. The ball check valve is opened by pressures above ball valve 72 which compress spring 73 and move ball valve 72 away from seat 68. The slots 70 provide for entry or discharge of fluids from below valve 72.

The upper end 55 of a pipe or string of tubing is screwed into the lower socket 25 of body 10, the tubing string extending down through the well head equipment and into the well. The socket 25 thereby serves as hanger 4 means for supporting the pipe or tubing string in the well.

To install the combined sealing plug and tubing hanger in the well head equipment, the lower element 12 is first set in place and connected to the well casing. The tubing string is then run into the well through element 12, the spring and barrier 51 set in place in sealing space 38, and the plug body 10 having the check valve means receivedtherein is screwed onto the upper end of the tubing string. The tubing string and body 10 are then lowered to seat the conical seat 27 on conical surface 40, after which the lockscrews 44 are screwed against seat 28. The lockscrews prevent the tubing string from being blown out of the well and O-ring packing 43 provides a seal around plug body 16 until the remainder of the equipment is installed and plastic sealant is forced into the upper part of sealing space 38 through fitting 52 and port 51. Upper element 11 may then be bolted above element 12, the spring 46 and barrier 45 being set in position in sealing space 37. It will be noted that the provision of lockscrews 44 and O-ring 43 make it safe to remove the customary blowout preventers before upper element 11 is installed, thereby making the remainder of the installation entirely safe and far easier than in the usual well head installation procedures. After the plug body 10 is once set in place and held down by the lockscrews 44, O-ring 43 providing a seal therearound, all of the well completion equipment above the plug body 10 may be safely installed without the use of blowout preventers or other safety equipment for preventing blowing out from the well.

While a preferred embodiment of the invention has been shown and described, many modifications thereof may be made by a person skilled in the art without departing from the spirit of the invention, and it is intended to protect by Letters Patent all forms of the invention falling within the scope of the following claims:

I claim:

1. A combined joint sealing and well pipe supporting device comprising plug means for lapping a joint between flow passages of upper and lower well completion elements, means for supporting said plug means at said joint, means for sealing around said plug means above and below said joint, a passage through said plug means across said joint, valve means removably disposed in said passage means, and pipe supporting means at the lower end of said passage means beneath said valve means for su porting a pipe in the well.

2, The combination of claim 1 including means for temporarily sealing around said plug means during installation of said plug means between said upper and lower well completion elements, and means for locking said plug means to said lower well completion element during said installation, whereby the said upper well completion element may be safely installed without the use of blowout preventers after said temporary sealing means and said locking means are installed.

3. Well completion apparatus comprising a tubing head, a tubing head adapter above said tubing head, a flangeconnected joint between said tubing head and said tubing head adapter, a passage through said tubing head to a well, a pipe within said tubing head passage extending into said Well and having an annularpassage space therearound, a passage through said tubing head adapter communicating with said tubing head passage at said joint, a plug means at said joint extending into said tubing head passage below said joint and into said tubing head adapter passage above said joint, means for sealing around said plug means below and above said joint, means for supporting said plug means at said joint, 21 vertical opening through said plug means having removable valve means therein, a pipe connecting means at the lower portion of said vertical opening for connecting said pipe to said plug means, said pipe being thereby supported in the well by said plug means, whereby said annular passage space is sealed from the interior of said pipe, from said flangeconnected joint, and from said tubing head adapter passage by said sealing means below said joint, whereby said tubing head adapter passage and the interior of said pipe is sealed from said flange-connected joint by said sealing means above said joint, and whereby said plug means provides hanger means to support said pipe in the well.

4. The combination of claim 3 including a recess formed around the upper end of said tubing head passage and a recess formed around the lower end of said tubing head adapter passage each adjacent said joint for receiving said plug means and said sealing means, said plug means having an upper and a lower outwardly projecting flange means each spaced from an end of said plug means and snugly receivable Within said respective adapter and tubing head recesses, and said sealing means being disposed in said recesses respectively above and below said upper and lower flange means at the ends of said plug means.

5. The combination of claim 4 including means for locking said plug means to said tubing head and means for temporarily sealing around said plug means in said tubing head passage, whereby said tubing head adapter and said means for sealing around said plug means below and above said joint may be safely assembled without blowout preventers after said locking means and said the well, comprising a recess around said passage in each of said elements and each recess being adjacent said joint, a body disposed within both of said recesses to bridge said joint and having a vertical opening therethrough to provide a continuation of said passage thereacross, tubing string connection means disposed at the lower end of said body around said passage continuation opening, said body having formed thereon two outwardly protruding flange means therearound each spaced from an end of said body and each disposed within and contacting the sides of one of said recesses, and a sealing means around each end of said body cooperating with the respective one of said flange means and recesses for forming a seal between said body and the respective one of said well head elements.

7. The combination of claim 6, each of said sealing means comprising, means for urging plastic sealing material contained in the recess to between the flange and recess sides contacted by the flange to form a seal therebetween, and a supply of said plastic sealing material in each recess between each said urging means and the flange cooperating therewith.

References Cited in the file of this patent UNITED STATES PATENTS 2,148,327 Smith et al. Feb. 21, 1939 2,150,887 Mueller et al. Mar. 14, 1939 2,293,012 Barker Aug. 11, 1942 2,589,483 Eckel et a1. Mar. 18, 1952 

